1. Field of the Invention
The present invention relates to a mobile communication network system and a locking method for a mobile terminal apparatus, and more particularly, to a mobile communication network system and a locking for a mobile terminal apparatus for preventing abuse by a third party when the mobile terminal apparatus such as a cellular telephone or the like is lost or stolen.
2. Description of the Prior Art
In recent years, cellular telephones have been becoming widespread that perform communication with an IC card referred to as a SIM (Subscriber Identification Module) card inserted therein. The SIM card stores an ID code such as a telephone number or the like corresponding to an owner (subscriber), while further storing personal data (such as, for example, data of memory dial with which are registered names of communicating parties of telephone numbers, data of a history of incoming calls and the like) of the owner. By using such a SIM card, for example, even when the owned cellular telephone becomes unusable (failure, battery exhaustion and the like), by inserting the SIM card in a cellular telephone of another person, it is possible to perform a telephone conversation using the ID code of the user.
However, in the case where the owner loses such a SIM card and the SIM card unintentionally falls into the hands of another person, there is a possibility that a call is placed maliciously by the person who acquires the SIM card, and that the personal data is read. To prevent such trouble, proposed is a mobile communication terminal where a lock code is stored in the SIM card, and by comparing the lock code with a lock code received from another communication terminal via a wireless communication channel, the operation on the mobile terminal apparatus body and access to the SIM card is locked (for example, Japanese Laid-Open Patent Publication No. 2003-70064).
However, in the aforementioned conventional mobile communication terminal, since the locking operation is performed based on the lock code and the like stored in a SIM card, when the SIM card is intentionally replaced, there is a problem that it is not possible to lock the operation on the mobile terminal apparatus body and access to the SIM card.
Particularly, in recent years, cellular telephones themselves become more sophisticated in functionality, and such a situation is assumed that a third party steals a cellular telephone of another person to insert a SIM card owned by the third party to use. However, in the above-mentioned conventional mobile communication terminal, unless owners of the cellular telephone and the SIM card agree with each other, the locking operation cannot be performed, and there is a problem that it is not possible to prevent such abuse.